Heating pads have been in use for some time for medical and/or therapeutic purposes. Specifically, the heat supplied from the pads have been used to warm body parts, and in particular muscle areas, to relieve such areas from the aches and pains associated therewith.
To maintain a substantially constant heat level over an extended period of time, heating pads have utilized electrical power to generate a source of heat by way of a resistor array. In some designs, the heating pads are provided with mechanisms for controlling (hereinafter "control units") the amount of power to the resistor array, so as to vary the level of heat generated. With such control units, the duration of power supplied to the heating pad is often continuous, thus resulting in a continuous generation of heat by the pad. To avoid continuous generation of heat, or at least until the heating pad is disconnected from a power source, such as an outlet, some control units have employed the use of a timer to cut off the supply of power to the resistor array, after a preset amount of time. In this manner, the control unit can determine the duration over which heat is generated from the pad.
Despite having a timer, there are some disadvantages associated with currently available heating pads. Specifically, the timers available with current heating pads are often designed with just one setting, usually for a duration of about sixty minutes. Thus, should the heat pad user wishes to stop using the heating pad prior to the expiration of the preset time period, the user may be inconvenienced by being forced to unplug the electrical chord which connects the heating pad to an electrical outlet in order to stop the supply of power to the heating pad. Subsequently, to initiate another use session, the user must remember to re-plug the electrical chord into the outlet prior to getting comfortable. Otherwise, the user must move from his comfortable arrangement to plug the electrical chord into the outlet.
The design of existing control units may also create potential hazards. In particular, should the user neglect to unplug the electrical chord from the outlet prior to moving away from the heating pad area for an extended period of time, the continuous supply of power to the heating pad, or at least for the duration of the timer period, without any supervision from the user may cause an accidental fire to be started. Moreover, the continuous supply of power to the heating pad without the use of same by the user would result in a waste of energy and thus money.
Accordingly, it would be desirable to provide a control unit which permits the user to vary the time period during which power is supplied to the heating pad. Furthermore, it would be desirable to provide the user with an option for a time period shorter than that currently available, so as to avoid any potential hazards, waste of energy, or frequent plugging and unplugging of the electrical chord from the outlet.